I got this recipe from the cucinafamiglia blog and it looks super yummy !
2 bags microwave popcorn (the natural kind)
2 cubes butter
1 bag of marshmallows
3/4 cup brown sugar
Pop popcorn and put aside in bowl. In microwave melt butter and marshmallows for about 1 minute. Stir and add brown sugar. Stirring until smooth. Pour over popcorn and mix together. Enjoy!